In recent years, a ceramic coating layer is formed on a kitchen appliance such as a rice cooker or the like in order to impart functionality such as non-stick performance to the kitchen appliance. On the other hand, various kinds of patterns (e.g., a reference line for adjusting the water level of a rice cooker, etc.) are printed or engraved on the kitchen appliance.
However, it is typically difficult to print such patterns on the ceramic coating layer. For example, when the ceramic coating layer is formed and then liquid ink is printed before the formed ceramic coating layer is cured, the ink spreads to thereby obstruct the patterns from being clearly printed. In addition, when the ceramic coating layer is formed and then liquid ink is printed after the formed ceramic coating layer is cured, a problem occurs in that the printed patterns are peeled off from the ceramic coating layer due to a weak mutual stickiness between the ceramic coating layer cured at high temperature and the liquid ink.
Therefore, typically, the inner surface of the rice cooker is cut away and then patterns such as a reference line and the like are engraved thereon, leading to a complexity of the manufacturing process and an increase in the manufacturing cost.
In an attempt to solve the above problem, there has been proposed a kitchen appliance having a ceramic print layer and a method for forming a ceramic print as disclosed in Korean Patent Laid-Open Publication No. 10-2003-0080753. In the above patent publication, a ceramic coating layer is formed on the inner surface of the kitchen appliance including a metal main body, and then ceramic ink is printed thereon in a semi-cured state and completely cured at high temperature. However, this ceramic print forming method entails a problem in that it is merely a partial change in the manufacture process and the used ink itself is not suitable for the ceramic coating layer, and thus a pattern is not printed properly on the ceramic coating layer. Furthermore, as an interest is currently increasingly focusing on environment and hygiene, the consumption of various kinds of antibacterial kitchenware is increasing. Therefore, there is a need for an antibacterial function for such a ceramic printing ink composition.